With the development of the mobile communications industry and the growing demand for mobile data services, the user's requirements for mobile communication rate and Quality of service (Qos) is increasing. Therefore, before the 3rd Generation (3G) mobile communication has been commercially applied in a large scale, research and development works of the next Generation mobile communication system have already started, and a relatively typical work is the Long Term Evolution (LTE) projection launched by the 3rd Generation Partnership Project (3GPP), and the highest spectrum bandwidth which can be provided by the LTE system is 20 MHz. With further evolution of the network, the LTE-advanced (LTE-A), as an evolved system of the LTE, can provide a spectrum bandwidth up to 100 MHz, and support more flexible communication with a higher quality, and at the same time the LTE-A system has a better backward compatibility. In the LTE-A system, there are multiple component carriers (CC), an LTE terminal can only work on a certain backward compatible CC, while an LTE-A terminal with a stronger capability can transmit on multiple CCs at the same time. This realizes that the LTE-A terminal transmits and receives data on multiple component carriers at the same time, so as to achieve the purpose of improving the bandwidth. The technology is referred to as multi-carrier aggregation technology.
In the research at this stage, on the basis of multi-carrier aggregation technology, the LTE R11 stage puts forward new requirements for aspects such as spectrum resource utilization, network energy saving, as well as inter-cell interference suppression. In order to achieve this goal, the New Carrier Type (NCT for short) is proposed currently. By means of the application of the carrier aggregation technology, the new carrier type has a distinct feature, i.e., there is no need to consider backward compatibility when designing, and more new technologies can be applied therein. For example, at present, in the LTE R11, the new carrier type is defined as follows: it needs to operate with at least one compatible carrier in a pairing manner (also referred to as operation with a compatible carrier in a carrier aggregation manner), and in the new carrier type, Cell-specific Reference Signals (CRS for short) of the LTE R8 are not configured, to avoid serious CRS interference of the adjacent cell at the edge of the cell, especially CRS interference between a macro cell and a micro cell in a scenario of HETerogeneous NETwork (HeNet).
Further, as the LTE R11 progresses slowly, finally in consideration that the standard work of the NCT cannot be completed within a time period, the related research on the NCT technology is put off until the LTE R12, and the contents accepted in the LTE R11 are still accepted. At present, the standardization work of the LTE R12 has not started, and many companies have believed that in the LTE R12, not only the NCT of the LTE R11 continues to be researched, but also it needs to further increase other NCT technologies, for example, a standalone NCT is proposed, which has an independent operation capability. In order to distinguish from the NCT in the LTE R11, as the NCT in the LTE R11 needs to configure a backward compatible carrier, it is referred to as a non-standalone NCT, which needs to operate with the help of a paired compatible carrier thereof as it deletes part of channels/signaling.
Further, in a standalone NCT, it has been determined that the positions of the Physical Resource Block (PRB) pairs occupied by a UE specific Search Space (USS) of an enhanced Physical Downlink Control Channel (ePDCCH) are notified through high-layer signaling, and in particular, are notified in a User Equipment (UE) specific manner. In this way, the PRB pairs of the USS of the UE may configure PRB pairs of the common USS for part of UEs which need them. For example, in the Coordinated Multi-Point (COMP), USSs of the UEs which require coordination are configured in the same PRB pairs through signaling respectively for the UEs, which is beneficial for the UE to reduce the search space, and would not affect configuration of PRBs of the USS of other irrelevant UEs.
With respect to notifying the positions of the PRB pairs of the USS of the ePDCCH of the UE through a UE dedicated Radio Resource Control (RRC for short) message, there are the following problems at present: In the process that the UE accesses in downlink until an RRC connection is established, a random access process is necessarily to be completed, wherein it needs to receive a Message 4 (msg4) as one of downlink messages in the random access process. If Downlink Control Information (DCI) for scheduling is transmitted in the USS of the UE for the msg4, it is a problem for the UE to acquire the position of the PRB pair where the USS of the UE is located. Another problem is that assuming the UE completes a random access process in another manner, the base station needs to transmit some dedicated RRC messages to the UE, and at this time, when the UE receives a first dedicated RRC message transmitted by the base station, the dedicated RRC message is transmitted through scheduling of the USS. In this case, there is a problem for the UE to acquire the positions of the USS for scheduling the first dedicated RRC message in the PRB pairs.
Obviously, according to the current conclusion, the PRB pairs of the USS of the UE are transmitted to the UE through a dedicated RRC message of the UE, it needs to firstly establish an RRC connection for transmitting the dedicated RRC message, and at present, in the process of establishing the RRC connection, the UE needs to acquire the positions of the PRB pairs of the USS, or the UE needs to acquire the positions of the PRB pairs of the USS when receiving the first dedicated RRC message.